Income Taxes - Additional Information (Detail)	6 Months Ended
	Mar. 31, 2021 USD ($)
Income Tax Disclosure [Line Items]
Unrecognized income tax benefits	$ 0
Federal
Income Tax Disclosure [Abstract]
Number of years for examination	4 years
New York
Income Tax Disclosure [Abstract]
Number of years for examination	4 years
Connecticut
Income Tax Disclosure [Abstract]
Number of years for examination	4 years
Pennsylvania
Income Tax Disclosure [Abstract]
Number of years for examination	4 years
New Jersey
Income Tax Disclosure [Abstract]
Number of years for examination	5 years